KR20130064744A - Method and device for carbon injection and recirculation of synthesis gas when producing synthesis gas - Google Patents

Abstract

The present invention relates to a method for introducing powder material (C) into gasification reactor (2), wherein process gas (P) supplied into gasification reactor (2) is converted into syngas (S) by powder material (C). Reduced and also the powder material (C) is introduced into the gasification reactor (2) through the inlet zone, and a negative pressure is generated in the inlet zone for the powder material (C) through the Laval nozzle (15) and also the process gas ( When P) passes through the Laval nozzle 15, a negative pressure is generated. The method also relates to an apparatus for doping powder material (C) into the gasification reactor (2). The process according to the invention is characterized in that the process gas P expands in the gasification space 5 in the gasification reactor 2.

Description

TECHNICAL AND DEVICE FOR CARBON INJECTION AND RECIRCULATION OF SYNTHESIS GAS WHEN PRODUCING SYNTHESIS GAS}

The present invention relates to a method and apparatus for the recycling and carbon injection of gases when syngas is produced from solid carbon particles, wherein the carbon particles are obtained by pyrolysis and the gasification of the carbon particles is in the same space where the carbon particles are located. Is produced by indirectly heating the carbon particles in the presence of a process gas, the reaction product is recycled and the syngas produced during gasification is released from the space. In order to achieve the best effect possible, the device accelerates gases at supersonic speed and also a negative pressure for the injection of powdered carbon and a Laval to generate a long dwell time for the gas and powdered carbon in the gasification reactor. It includes a nozzle (Laval nozzle).

In order to allow the gasification of carbon-bearing materials in the gasification process, a device for carbon injection is required when producing carbon-synthetic gas.

The process for producing gaseous fuel from solid fuel is gasification. This technique is used for coal, by-products of coal, petroleum residues, waste and biomass. The reaction is heated by substoichiometric combustion and then is endothermic: carbon ([C] reducing agent), carbon monoxide (CO) and hydrogen (H ₂ ) formed as heat is consumed to carry out the reactions. Based on oxidizing gases (e.g., CO ₂ and H ₂ O). The gas mixture of carbon monoxide (CO) and hydrogen (H ₂ ) is called syngas here.

One common gasification method is high subchemical combustion of carbon-containing materials while supplying superheated steam. Although not combusted, superheated carbon reacts with the supplied fuel gas and steam. Carbon (C) reduces carbon dioxide (CO ₂ ) to carbon monoxide (CO) and also reduces water vapor (H ₂ O) to hydrogen (H ₂ ). Heat dissipated lowers the temperature and also reduces reactivity. Carbon reactivity is temperature dependent, while the equilibrium of the reaction is temperature dependent. Although air-based combustion is found, oxygen-based combustion is now the leading combustion method for gasification. Most processes are based on pressurized systems. Steam and oxygen are easily pressurized but rarely cause problems. For example, the introduction of a pulverulent material into the reactor means that there is a pressure difference between the atmosphere outside the gasification reactor and the inside pressure, which must be overcome.

Problems associated with the gasification of carbon-containing materials such as coal, coal by-products, petroleum residues, wastes and biomass, as mentioned above, have significantly higher temperatures over a fairly long period of time to achieve complete gasification of the carbon-containing materials. And sufficiently reduce the reducing agent (carbon) and oxidizing gases (CO ₂ and H ₂ O) and overcome the pressure difference between the atmosphere outside the gasification reactor and the inside. If time and temperature cannot be maintained, the reaction may not be carried out completely, and insufficient mixing may lead to incomplete reactions.

The present invention is a device for carbon injection that injects powdered material into a tubular injector when producing syngas, wherein the solid material enters the center of the reactor, and also carbon is sucked into the injector and also carbon is distributed into the gasification reactor. Laval type surrounding nozzles, which oxidize gases to produce strong negative pressures, perform pressure increases, prolong residence times in the reactor, and also create homogeneous mixing in the reactor. The momentum of the oxidizing gas causes various mixing of the syngas in the gasification reactor with the oxidizing gas being introduced and the material. The negative pressure produced by the gas momentum can be controlled by recycling a portion of the syngas in the gasification reactor through an injector in the channels provided at the end of the reactor.

It is a first object of the present invention to provide a device of the type defined in the introduction, and an essential principle of the invention is to create a negative pressure to facilitate the introduction of the powder material into the gasification reactor with an injector.

Another object of the present invention is to generate various agitation between oxidizing gas and powder material when the oxidizing gas and powder material is introduced into the gasification reactor and also to recycle the syngas in the gasification reactor to achieve uniformity of temperature and elements. It is. This leads to longer residence times in the reactor, resulting in smaller and more economical reactor designs.

Another object of the present invention is to recycle the synthetic dew through the injector in this way and to control the negative pressure as the powder material is introduced into the gasification reactor.

At least a first object of the invention is achieved by an apparatus having the features specified in the independent claim 1. Preferred embodiments of the invention are defined in the dependent claims.

According to the present invention, the strong negative pressure from the Laval nozzle has the effect of controlling the ratio between the carbon and process gas flow in the gasification reactor, thus achieving an optimum reaction state.

1 is a schematic diagram of an apparatus for carbon injection when generating syngas in accordance with the present invention, the schematic diagram showing a unit forming an apparatus for performing carbon injection in a tabular format.
2 is a schematic diagram of one embodiment for carbon injection when generating syngas in accordance with the present invention, the schematic diagram showing units forming a device for performing carbon injection in tabular form.

Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a gasification in which powder carbon (C) is supplied to an injection nozzle (1) in which powder carbon (C) is mixed with process gas (P) (preferably steam) and recycled reaction product (R _s ) (synthesis gas). A diagram showing a device for carbon injection in a process. The mixture from the injection nozzle 1 is heated and reacts in an indirectly heated gasification reactor 2. To this end, the gasification reactor 2 comprises a burner 4 which extends into the gasification space 5 in the gasification reactor 2, which burner 4 provides heating directly to the gasification reactor 2. The process gas P is pressurized through the annular Laval nozzle 15 integrated in the injection nozzle 1 and accelerated at sonic speed (Mach> 1). The Laval nozzle 15 is provided for the center of the injection nozzle 1 and the powdered carbon C and the recycle reaction product R _s (synthetic gas) which are incorporated into the injection nozzle 1 which is led into the gasification vessel 2. Create a strong negative pressure in the center tube / center channel 6.

The region through which the central tube 6 of the injection nozzle 1 passes into the gasification vessel 2 defines an inflow region for the powdered carbon C. A negative pressure in the center / inlet region of the injection nozzle 1 sucks in powdered carbon C and also recycles the reaction product R _s , where the three streams are mixed and the gasification reaction starts. The process gas P flowing at supersonic speed through the annular laval nozzle 15 is further recycled at the periphery of the nozzle. Additional reaction product is introduced into the gasification mixture from the injection nozzle 1 at the center of the mixing zone M directly in front of the injection nozzle. The heat from the recycled reaction product (R _S ) is rapidly raised to the reaction temperature required for the gasification process of the injected powder carbon (C) and process gas (P) by assisting indirect radiant heat in the gasification reactor (2).

Pipes, tubes, etc. connecting the units of the facility are not described in detail or shown. Pipes, tubes and the like are designed in a manner suitable to carry out their functions, ie in a manner suitable for transferring gases and solid material between units of a facility.

1 shows the principle of an injection nozzle 1 connected to an indirectly heated gasification reactor 2. The injection nozzle 1 has a Laval nozzle 15 for the process gas P, which accelerates the process gas P at supersonic speed. An annular laval nozzle 15 is arranged outside the center tube / center channel 6. Syngas S in the process is mainly produced in the gasification reactor 2.

Solid carbon particles (C) are supplied to the injection nozzle (1) together with the process gas (P) and with the recycled secondary reaction product (R _S ). The negative pressure for the carbon injection can sometimes be controlled depending on the fact that the secondary reaction product R _S flows through the independent channels 14 in the injection nozzle 1. Carbon particles (C) may preferably originate from pyrolysis prior to gasification. The size of the carbon particles (C) is preferably made to provide the fastest reaction in the reactor. Process gas P may be steam or may be recovered from a combustion step of heating the reactor and also purified flue gas. If the process gas P is a recovered flue gas, the flue gas may include water vapor (H ₂ O) and carbon dioxide (CO ₂ ). Process gas P is generally preheated by heat recovered from syngas S discharged from the downstream heat exchanger. Process gas P generally has a sufficiently high excess pressure with respect to reactor pressure to achieve supersonic speed. Process gas P with velocity Mach> 1 produces a strong momentum in gasification reactor 2. The pressure of the steam depends on the temperature outside the heat exchanger. If flue gas is used instead of steam, the pressure of the recycled flue gas is generally generated by a compressor. The momentum of the process gas P outside the injection nozzle 1 allows the secondary reaction product R _S to be introduced into the reaction zone R from the mixing zone M. The reaction taking place in the gasification reactor 2 is that carbon (C) reduces the process gas (P) (H ₂ O and CO ₂ ) contents to syngas (S) (H ₂ and CO). The reduction consumes the heat supplied to the process by the burner 4 which indirectly heats. Heat is supplied to the gasification reaction by radiation from the burner 4 and combustion takes place inside the radiant tube, providing a flue gas in which the fuel F and the oxidant O are burned and separated from the gasification flow. . There is no direct gas production between burner 4 and process gas P or its reaction product in gasification reactor 2. By imparting supersonic speed to the process gas P, the injection nozzle 1 can provide an extended residence time in the reactor 2 and the gasification reaction can be carried out close to equilibrium. This also allows the largest degree of burn-out to the carbon particles C.

Emitted syngas (S) can be used as an energy gas for combustion purposes or as a basis for further purification to liquefy fuels (Fischer- for typical vehicle fuels, methanol products, etc.). Tropsch process).

The injection nozzle 1 is designed to handle different system pressures in the gasification reactor 2. The pressure in the reactor 2 can be controlled from atmospheric pressure to very high pressures (> 100 bar). The injection nozzle 1 is typically designed to have a ceramic part suitable for ceramic lining in the gasification reactor 2 and an outer part made of heat-resistant steel, with carbon (C), process gas (P) and Channels for the recycled reaction gas R _S are located and ultimately together exposed out of the bottom of the nozzle. The injection nozzle must always have a supply pressure with the process gas P higher than the system pressure in the gasification reactor 2. This pressure difference also creates a strong negative pressure with respect to the mass flow of the process gas P since the pressure is higher than a standard injector with straight tubes. This strong negative pressure from the Laval nozzle 15 is beneficial to control the ratio between the mass of carbon (C) and the process gas (P) in the gasification reactor (2), thereby achieving an optimal reaction state.

To achieve the maximum yield of syngas S, the choice of material for the injection nozzle 1 depends on the temperature in the gasification reactor 2 which depends on the reaction temperature. Typical lampshades are in the range of 900-1300 ° C. The choice of material for the ceramic and metal parts in the injection nozzle 1 is made to suit the selected temperature level. In the reaction zone (R) the temperature uniformity, as a result of the recycling of the injection nozzle (1) within the channel (3) reaction gas (R _S), a reactive gas (R _S) part also through the mixing zone (M) of the through the This can be done much faster than in the case of regular injection nozzles.

Syngas S (H ₂ and CO) from gasification reactor 2 contains not only hydrogen and carbon monoxide, but also a certain amount of carbon dioxide and methane depending on the components of the process gas P introduced and the temperature selected. It includes.

2 shows an embodiment of an apparatus for carbon injection when introducing syngas. The injection nozzle 1 is composed of a metal part 11 and a ceramic part 13 forming one unit. The injection nozzle has a Laval nozzle 15 for the process gas P, through which the pressurized gas is accelerated at supersonic speed. Powdered carbon (C) is typically supplied to the central tube / central channel (6) by means of a feed screw and a plug flow, in which the powder is recirculated through the other channels (14). It is mixed with the product (R _S ). Process gas P (preferably steam) is supplied to the Laval nozzle 15 via a connection 12 through a ceramic tube, where an overpressure of process gas (steam) expands (+ p) outside the nozzle Strongly accelerated at supersonic speed (Mach> 1) by a Laval nozzle (15) and having negatively charged powder carbon (C) and recycled reaction product (R _S ) entrained in the mixing zone (M) Produces a pressure (_p), the periphery of the Laval nozzle 15 also produces a negative pressure (-p) and also recycles the reaction product (R _S ) into the mixing zone (M).

Possible Modifications of the Invention

In an alternative embodiment, the injection nozzle can be used for a mixture of process gas and additional oxygen as described above, which significantly increases the temperature in the mixing zone (R) and reaction zone (M).

In another alternative embodiment, the injection nozzle is horizontal, and the carbon injection (C) is in the horizontal plane or as close to the horizontal plane as the process allows.

The supply of powdered carbon (C) can be carried out by the inlet piston instead of the feed screw as described here in FIG. 2. Another alternative is to use a lock feeder to supply powdered carbon (C) to the vertical tube in the injection nozzle in an airtight transfer through a fluidized channel.

Using hermetic carbon supply systems exposed to negative pressure, the pressure-regulating channel 14 of FIG. 2 can be minimized or omitted.

In the embodiment described above, the secondary reaction product R _S is recycled through the channels 14 arranged in the injection nozzle 1. As an alternative to this arrangement, the syngas S discharged from the gasification reactor 2 can be recycled into the central tube / central channel 6 of the injection nozzle 1. From a purely particle point of view, this can be done by recirculation pipes arranged outside the gasification reactor 2.

Claims (8)

As a method for introducing the powder material (C) into the gasification reactor (2), the process gas (P) supplied into the gasification reactor (2) is reduced to the syngas (S) by the powder material (C) and also the powder material. (C) is introduced into the gasification reactor (2) through the inlet zone, a negative pressure is generated in the inlet zone for the powder material (C) by the Laval nozzle (15) and the process gas (P) A method in which a negative pressure is produced when passing (15), wherein the process gas (P) expands in the gasification space (5) in the gasification reactor (2). 2. The powder material of claim 1, wherein the powder material consists of powdered carbon (C) and the secondary reaction product (R _S ) is mixed with the powdered carbon (C) when the powdered carbon (C) is introduced into the gasification reactor (2). How to feature. The negative pressure generated in the inlet zone sucks in particles and gas located in the gasification reactor (2), so that the gases and particles in the gasification reactor (2). Extending the residence time. The negative pressure generated in the inlet zone causes recirculation of gases and particles in the gasification reactor (2) to compensate for the difference in concentrations in the gas components and to the gasification reaction. To compensate for temperature changes in accordance with and minimize the stationary bed around the burners (4) arranged in the gasification reactor (2). An apparatus for introducing the powder material (C) into the gasification reactor (2), wherein the process gas (P) supplied to the gasification reactor (2) is reduced to the syngas (S) by the powder material (C). Consisting of an injection nozzle 1, the injection nozzle 1 is provided with a central tube / central channel 6 for introducing the powder material C into the gasification reactor 2 and the injection nozzle 1 is a central tube. An apparatus comprising a laval nozzle 15 arranged outside of (6),
The center tube / central channel (6) is characterized in that it passes directly into the gasification space (5) in the gasification reactor (2). 6. Device according to claim 5, characterized in that the Laval nozzle (15) is arranged at the end of the injection nozzle (1) oriented towards the gasification space (5) in the gasification reactor (2). The injection nozzle (1) according to claim 5 or 6, wherein the injection nozzle (1) comprises additional channels (14) for the recycling of the secondary reaction product (R _S ) and the additional channels (14) are also gasified in the gasification reactor (2). Device in communication with the central tube / center channel (6) in the region of the end of the injection nozzle (1) oriented away from the space (5). 8. Device according to claim 7, characterized in that the cross sectional dimensions of the additional channels (14) can be varied to adjust the negative pressure generated by the Laval nozzle (15).

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